To many people, music provides escapism. It allows for the diversion of thoughts and, perhaps for some, the submission into emotional states of mind that we didn’t quite realise we were experiencing. However, for a small population of individuals, their relationship with music is essentially pathological due to the fact it triggers seizures. Termed musicogenic epilepsy, this condition is a rare form of complex epilepsy where patients report seizures that are induced by music. Described by a character in Coelho’s The Zahir as ‘an ecstatic experience provoked by hearing a particular kind of sound’, patients with musicogenic epilepsy can be sensitive to music of a particular genre, a particular instrument, or in extremely intriguing cases, a specific singers voice. Some patients have actually named the singer Sean Paul as a stimulus for their seizure activity, and can therefore no longer listen to his music (note – some may argue that this is not a shame) (Swaminathan, 2008).
Many people are aware that epilepsy is a condition where the neurons of the brain fire abnormal electrical signals, essentially resulting in an overload of electrical activity in the brain. There are numerous types of seizures that each present with different symptoms. Localisation of the excess electrical activity in the brain has allowed for scientists and clinicians to determine which types of seizures result from excess activity in particular brain regions. Frontal lobe epilepsy, for example, is the second most common type of epilepsy that can present as a partial seizure, i.e. the seizure is initially localised to just one hemisphere of the brain. As the frontal lobe of the brain contains many regions associated with motor function, tonic posture and clonic movements, such as facial grimacing and automatisms, are largely associated with seizures in this area of the brain (Schachter, 2013).
Musicogenic epilepsy (ME) has been assumed a rare condition due to the fact less than 200 cases have been reported; however clinicians argue that many epileptics may suffer from musicogenic seizures without actually realising it. Of the reported cases, it has been found that ME is increasingly common in individuals who are exceptional musicians and who possess sophisticated musical understanding. Our understanding of the physiological mechanisms underlying the triggered seizures has been enriched mainly by single case report studies. The ability to provoke seizures in patient’s known to have ME provides researchers with greater insight into the process of seizure initiation and propagation.
Such research includes the work of Mehta et al. (2009). The scientists conducted extensive research to discover the underlying brain regions involved in ME, adopting PET scans and EEG recordings to collect their data. An EEG recording is commonly used in clinical neurophysiology to confirm a patient is suffering from seizures. The test works by attaching many electrodes to various points of the scalp and recording a potential difference between select electrodes. This therefore allows the detection of abnormal electrical activity in the brain and also allows for localization of the activity. The participant for the study, a 24-year-old female, had been suffering from epilepsy for two years preceding her acknowledgement that music was a trigger.
In the study, three seizures were recorded during a period of 1 week. All three seizures were music provoked, and the pattern of spread across the brain was consistent. The PET scans showed the location of seizure onset as being in the right mesial temporal lobe – the lobe that contains the auditory cortex and so processes sound information. This was followed by sequential spreading to the parahippocampal gyrus and the amygdala, and eventually the lateral temporal lobe. These regions of the brain are extremely interesting, as they are largely associated with emotional processing – linking back to the previously mentioned idea that music is a form of escapism and allows us to uncover deeper emotions. As an approach to treatment, the case study participant underwent a right temporal lobectomy (in non-scientific terms this translates to ‘they removed the region of the brain found to be associated with the seizures’). The patient was discharged and upon follow up 9 months later was found to be seizure free and able to listen to the music that once initiated her seizures. That, in my opinion, is pretty remarkable neuroscience.
Evidently, it has to be taken into consideration that due to the small number of reported cases, the research surrounding ME remains fairly limited and is subject to critical review. However, studies such as work by Mehta et al (2009) are revealing more and more about the complexity of the condition, which, even if you may not consider yourself a scientist, is still absolutely fascinating! The seizures appear to be associated with the emotional and limbic processing of both sound and music, and onset predominantly favors the right hemisphere of the brain. Music is believed to induce a pattern of activity within a network of neurons in multiple brain areas, including the primary auditory cortex and association cortex. Such neurons then project to the hippocampus and amygdala regions where the memory of the music is stored in addition to the emotional response that we feel when we hear the music. One theory suggests that if this neuronal network coincides with that involved in a seizure of some description, then an association may form, resulting in greater likelihood of seizure activity upon activation of the neuronal network by repetition of the music. What weird and wonderful mischief the brain is capable of!
Author: Molly Campbell